Antioxidant and Antimicrobial Activities of Methanol and Water Extracts of Fruits, Leaves and Seeds of Vitis vinifera L. cv. Karaerik

Abstract

Antioxidant and antimicrobial studies were performed on methanol and water extracts of leaf, fruit and seed of Vitis vinifera L. cv. Karaerik. Lipid peroxidation inhibition, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and the amount of total phenolic compounds present in the extracts were determined. All parts of the plant have antioxidant potential. While seeds have the highest antioxidant potential, fruits have the lowest one. Antimicrobial activities of the above extracts were also tested against 96 clinical isolates of bacteria strains (Enterobacter aerogenes, Escherichia coli, Proteus miribalis, Pseudomonas aeroginosa, Staphylococcus aureus) and 90 Candida strains (Candida albicans, Candida glabrata, Candida guillermondii, Candida kefyr, Candida krusei, Candida parapisilosis, Candida pseudotropicalis, Candida tropicalis, Geotricum candidum) by disc-diffusion method and minimal inhibitory concentration (MIC) values of each active extract were determined. Water extracts of the grape leaves had shown the anticandidal activity against 3 Candida spp. (C. albicans, C. glabrata, C. tropicalis) and 1 bacteria species (S. aureus), and methanol and water extract of it have shown antibacterial activity against only Staphylococcus aureus with 13 mm inhibition zone and 0.625 mg/mL MIC value amoung the tested microorganisms. The highest anticandidal activity of leaves extract was found to be in their water extract against Candida albicans with 20 mm inhibition zone and 1.25 mg/mL MIC. Each one of the water and methanol extracts of seeds had shown antibacterial activity against three bacteria with inhibition zone range of 10-30 mm and 0.312- 2.5 mg/mL MIC values. The highest activities were shown by water and methanol extracts of the seed against Staphylococcus aureus with 30 mm inhibition zone and 0.312 to 0.156 mg/mL MIC values, respectively. Unlike leaves and seeds extracts, none of the fruits extracts had shown antimicrobial activity.